Bearing apparatus for a wheel of vehicle

摘要

A vehicle wheel bearing apparatus with a back-to-back double row tapered roller bearing has an outer member integrally with a body mounting flange and double row outer raceway surfaces tapered open respectively axially inward and outward. An inner member include a wheel hub and an inner ring or an outer joint member of a constant velocity universal joint. The wheel hub has a wheel mounting flange and one inner raceway surface arranged oppositely to one of the double row outer raceway surfaces and a cylindrical portion. The inner ring or the outer joint member of a constant velocity universal joint are press fit onto the cylindrical portion and include the other inner raceway surface arranged opposite to the other raceway surface of the double row outer raceway surfaces. Double row tapered rollers are freely rollably held between the outer and inner raceway surfaces by cages. Seals are arranged in annular openings formed by the outer and inner members. The cages are formed of synthetic resin. Posts between pockets of the cages are arranged to be positioned radially inward of the pitch circle diameter of the tapered rollers. The width of an opening radially inward of each pocket is set so that each tapered roller is held within the pocket. The contacting tapered surfaces of the posts open radially outward so that the rollers do not fall out radially inward.